Comparison of cardioprotective and anti-inflammatory effects of ischemia pre- and postconditioning in rats with myocardial ischemia–reperfusion injury

Abstract

To compare cardioprotective and anti-inflammatory effects of ischemia preconditioning (IPC) and ischemia postconditioning (IPOC) in a rat myocardial ischemia-reperfusion injury (IRI) model. Forty Sprague-Dawley rats were randomly divided equally into four groups. In the groups other than the sham group, the left anterior descending coronary artery was ligated for 30 min followed by a 180 min reperfusion in vivo. The control group was subjected to no additional intervention, the IPC group to three cycles of 5 min ischemia separated by 5 min reperfusion before the index ischemia and the IPOC group to three cycles of 10 s ischemia separated by 10 s reperfusion immediately after the end of the index ischemia. Hemodynamic changes during the ischemia and reperfusion were recorded. At 180 min of reperfusion, serum concentrations of troponin I (TnI), tumor necrosis factor α (TNF-α) and high-mobility group box 1 (HMGB-1) were assayed, and the infarction size was assessed by Evans blue and triphenyltetrazolium chloride staining. Compared to the control group, infarct size and serum concentrations of TnI, TNF-α and HMGB1 at 180 min of reperfusion were significantly reduced in the IPC and IPOC groups. However, infarct size and serum concentrations of TNF-α and HMGB1 at 180 min of reperfusion were significantly increased in the IPOC group compared to the IPC group. In the rats with myocardial IRI in vivo, both IPC and IPOC can produce significant cardioprotective and anti-inflammatory effects. However, cardioprotective and anti-inflammatory effects provided by IPOC are weaker than with IPC.